In the context of wireless communications, when measuring time of arrival (ToA) in multipath environment, a receiver typically receives multiple components each of which representing a distinct path. The shortest path between the transmitter and the receiver is often the path along a line of sight (LoS). The first signal that arrives at the receiver is referred to as the LoS component. The time it takes for the LoS component to travel from the transmitter to the receiver is the time used for calculating the distance between the transmitter and the receiver. However, as the signal strength of the LoS component tends to be weak compared to the signal strength of non-LoS components, it is difficult to identify and measure the time of the LoS component. For example, as shown in FIG. 3, the LoS component may be barely identifiable or not even identifiable due to its weak signal strength compared to the noise while the non-LoS components are stronger in signal strength and hence relatively more identifiable. This would result in a non-LoS component being mistakenly identified as the first component, and hence the “LoS component”, and consequently lead to inaccuracy in the measurement of ToA and calculation of distance.
In some cases, there may be one or more non-LoS components that arrive at the receiver very close in time to the arrival of the LoS component. This also makes it difficult to identify and measure the ToA of the LoS component.
The Detailed Description references the accompanying figures. In the figures, the left-most digit(s) of a reference number identify the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference like features and components.